1. Field of the Invention
This invention relates generally to security systems and more particularly is directed towards a new and improved electronic security system for use on motor vehicles or at sites such as homes, offices, or the like.
2. Description of the Prior Art
Various types of security systems have been developed for use with motor vehicles, offices, homes, or the like, to prevent unauthorized entry and theft. Automobile security systems have included such mechanical devices as conventional door locks or steering wheel locks, either controlled by the ignition key or by a separate collar. Typically, present stand-alone deterrent systems provide by design some interface to authorized persons which can, in turn, be used by unauthorized persons to violate the system. Examples are wires and cables which can be accessed by using small portable tools and then shunted or otherwise manipulated. Devices that operate off locks, on the other hand, can be pulled, picked or deciphered. Door locks are easily defeated, and the ignition key-steering wheel locks can also be rendered inoperative by a professional thief. Separate steering wheel collars are somewhat awkward to install, are not easily stored, and provide no protection for the contents or extremities of the vehicle. More sophisticated electronic or electro-mechanical systems have been developed but these have not been entirely satisfactory from the standpoint of cost, effectiveness and operating convenience. For example, alarms that are armed by means of a mechanical fender lock or the original equipment ignition lock are defeated by the lock being punched or pulled out and a by-pass shunt or substitute lock cylinder inserted. The secret locations of kill switches that turn off ignition or gas line valves can be disclosed by service or dealer personnel. They also provide no protection for vehicle contents or extremities. Ignition cut-off and alarm systems are easily disconnected or shunted around unless located under a locked hood. Current hood locks, even those requiring both vehicle entry and a separate key, are easily defeated by shunting electric locks or pulling mechanical locks and cables. Alarm systems that are controlled by magnetic card devices that are actuated only by movement of the card cannot continuously monitor the presence of the card. This may cause the operator to forget and leave the card in place or to leave a machine on while unattended. A hard wired (unbuffered), coded ignition cut-off may be by-passed by opening the hood, or the code utilized is deciphered by testing electrical values of the pins in the connector circuit. Dialed or key pad coded systems are awkward and cause dangerous delays to users threatened with criminal attack.
Most systems of the foregoing type, if they use an alarm, normally result in the battery being run down if the alarm is tripped and not turned off manually. Alarm systems also fail if headlights are accidentally left on when the vehicle is vacated. Systems of the foregoing type also have lacked flexibility in providing for security not only of the vehicle itself but also of various access points, or accessories, extremities and contents and do not include other important security features such as manually-operated alarms for panic situations. Also, such systems are not readily adaptable to other applications such as providing security for and access to homes, offices, laboratories, copy machines, and the like.
Accordingly, it is an object of the present invention to provide a convenient alarm and control system which is readily adapted to either vehicle or building use and adapted to monitor a number of different access points and accessories. Another object of this invention is to provide a flexible, efficient security system which is virtually invulnerable to being defeated by one not in possession of an electronically coded device uniquely matched to the security system.